Adding a further question, should I file a bug against the combined
rad-hat menu? it waits til it is first clicked on to check for
updates. The Gnome default menu (three buttons applications, and the
other two) seems to work straight away.

Which updates?

It has probably something to do with caching, as I believe gnome was
looking into adding cache's for its menu? or maybe it is regenerated
with the startup of gnome? (then the redhat menu should also be
regenereated at ots startup.)

The combined menu seems to have got faster since yesterday I think...
but it still takes a noticeable amount of time, as (I assume) it is
looking for the desktop files after being clicked on for the first time.

How many seconds of difference is there between the RH menu and the
stock GNOME menu?